 var currentPage = 0;

    $('.book')
    .on('click', '.active', nextPage)
    .on('click', '.flipped', prevPage);

    $('.book').hammer().on("swipeleft", nextPage);
    $('.book').hammer().on("swiperight", prevPage);

    function prevPage() {

    $('.flipped')
        .last()
        .removeClass('flipped')
        .addClass('active')
        .siblings('.page')
        .removeClass('active');
}
    function nextPage() {

    $('.active')
        .removeClass('active')
        .addClass('flipped')
        .next('.page')
        .addClass('active')
        .siblings();


}